Soil loss minimization as a function of forest size and location in a “water conservation program”
01/Dec/2011
As conflicts related to the water use in Brazil are increasing, the implementation of policies that can mitigate these problems has become crucial. In this context, the concept of Payment for Environmental Services (PES) has been widely accepted and applied around the world and also in Brazil. The municipality of Extrema, in the State of Minas Gerais, was the first in Brazil to implement a PES program, known as “Conservador das Águas”. This study aimed to evaluate soil losses in […]
Inter-relation between soybean yield and soil compaction under degraded pasture in Brazilian Savannah
01/Oct/2011
The Cerrado (Brazilian Savannah) plays an important economic and financial role in the nation, since the pastures of this biome feed cattle for half of the domestic bovine meat productivity, and its agricultural fields produce a third of the country’s grain. The variability and spatial dependence between the soil physical attributes and soybean yield were evaluated in a crop rotation planted on a degraded brachiaria pasture, on a dystroferric Red Latosol of an experimental farm of the State University of […]
Effect of 15n-labeled hairy vetch and nitrogen fertilization on maize nutrition and yield under no-tillage
01/Aug/2011
This study evaluated the effect of hairy vetch (Vicia villosa Roth) as cover crop on maize nutrition and yield under no tillage using isotope techniques. For this purpose, three experiments were carried out: 1) quantification of biological nitrogen fixation (BNF) in hairy vetch; 2) estimation of the N release rate from hairy vetch residues on the soil surface; 3) quantification of 15N recovery by maize from labeled hairy vetch under three rates of mineral N fertilization. This two-year field experiment […]
New approach to the Brazilian model of environmental services
01/Jun/2011
The Brazilian program of environmental services, called “Water Supplier”, is based on financial incentives relative to the erosion reduction by the implementation of voluntary soil conservation projects by farmers. However, this program has no pre-established restrictions of eligibility of application areas or conservation proposals. With a view to contribute to the methodological development of this program, a new approach was proposed, by analysis of two main changes: introduction of eligibility criteria, and the use of land suitability for recommendation of […]
Vertical mulching as a soil conservation practice to manage runoff in no tillage systems
01/Dec/2008
In regions of temperate and subtropical humid climate in Brazil, below the parallel of 24° latitude South, the rainfall characteristics potentially exceed the soil water infiltration rate and produce runoff, at any time of the year, independent of soil use and management system. The additional conservational practices have not been fully adopted in the no-tillage system as it would be required to control the erosion potential due to the soil conditions of these regions. Runoff results in chemically enriched sediments, […]
NetErosividade MG: rainfall erosivity for Minas Gerais State, Brazil
01/Jun/2008
Rainfall erosivity represents the potential of rainfall causing soil erosion. This study aimed to develop a software to estimate rainfall erosivity in the state of Minas Gerais based on Artificial Neural Networks (ANNs). The annual value of the rainfall erosivity is given by the sum of the monthly values of the erosivity indexes EI30 or KE > 25. Two methodologies were used to estimate the kinetic energy for each index. Thus, four erosivity values were evaluated for each month, resulting […]
Comparison of soils used for agroforestry and of remaining forests, in northern Rondônia State, Brazil
01/Apr/2008
The importance and efficiency of agroforestry systems in the conservation of tropical soils need to be demonstrated at the local scale. Physical and chemical soil attributes of seven plots used for agroforestry during 5.5 years were evaluated in the 0-0.2 m layer and compared with the respective soils of adjacent forests fragments in the Northern Rondônia State. No differences in texture were found between the soils in the layer evaluated, indicating that the two systems are located on the same soil type. […]
Calibration of phosphorus fertilization rates for main grain crops under no-till in Paraguay
01/Dec/2007
Presently, approximately 60 % of the grain crop area in Paraguay is under no-till (NT). With the expansion of NT in the country, some doubts were raised with respect to the obsoleteness of fertilizer recommendations, especially regarding phosphorus (P). The last P fertilizer recommendation had been established for conventional soil tillage system 15 years earlier. The main objective of this work was to update phosphate fertilizer recommendations for wheat, corn and soybean under NT. Seven different locations in eastern Paraguay were evaluated […]
Soil Quality Evaluated by “Soil Quality Kit” in two long-term soil management experiments in Rio Grande do Sul State, Brazil
01/Feb/2007
The soil quality (SQ) evaluation is an important part of agricultural planning. It allows the identification and improvement of high-yielding management systems with characteristics of environment preservation. This study was carried out in two long-term soil management experiments (10 and 15 years) in Rio Grande do Sul State, Brazil. The main objective of this study was to evaluate the effectiveness of the Soil Quality Kit (SQK) developed by the Soil Quality Institute – ARS – USDA, compared to traditional soil science […]
Estimates of rainfall erosivity in São Paulo state by an artificial neural network
01/Dec/2006
Knowledge on rainfall erosivity (R) of particular sites is fundamental for soil loss estimation by the Universal Soil Loss Equation (USLE) and therefore highly important in conservation planning. In order to obtain the R value estimates for places where it is unknown, an artificial neural network (ANN) was developed for the state of São Paulo, and its accuracy compared with the Inverse Distance Weighted (IDW) interpolation method. The developed ANN presented a smaller mean relative error in the R estimation […]